Installation manual

Portable Installation Cable: Practical cable for portable system interconnections is flexible, two-
conductor, shielded microphone cable. We suggest using BELDEN #8413 (24 Gauge). For runs
longer than 500 feet use a 20 gauge cable or larger (BELDEN #8412).
Permanent Installation Cable: Vinyl-jacketed shielded pair is the cable of choice for permanent
installations. Placing the cable in conduit is recommended but not necessary.
INSTALLING THE STATIONS
First, choose the location for the Main Station or Power Supply. These units require access to AC
power. They should be located away from other equipment that generates excessive amounts of heat.
Also, choose locations for each Remote Station and Speaker Station. Choose general locations and
areas of use for the beltpacks. Determine the locations for other Clear-Com equipment which will con-
nect to the intercom lines. The choice of location will depend upon and often define the wiring scheme.
It is very helpful to create a drawing showing where each component will be located as well as where
the wiring will run.
Connections
The following sections describe the connections provided on the intercom stations:
Intercom Line Connection:
The rear panel of Main Stations, Power Supplies, Remote Stations,
and other stations contain between one and three 3-pin male XLR connectors for each intercom line.
These connectors are wired in parallel. Any single-channel station or channel of a multi-channel
station connected on a line plugged into Channel A of the a Main Station will be "party-lined" with all
the other stations on that channel. In a multi-channel system, the goal is to assign specific people
to the correct group, i.e. the other people they need to be in contact with the most. This is particu-
larly important when the party line users are on a single-channel beltpack or station; less so if they
are on multi-channel stations. The pinout of the intercom connectors is as follows:
Pin 1 --- Ground (Shield)
Pin 2 --- Power (+30 VDC)
Pin 3 --- Audio
Line Termination:
The fundamental concept of Clear-Com Party-Line intercom is that all channels
are terminated in one location, preferably at a Main Station or Power Supply.
CAUTION
:
All intercom lines must be terminated. Care must be taken not to
'"double-terminate" a line. All unused intercom lines must also be terminated.
Switching of the channel terminations ON and OFF is done with switches or jumpers on the Main
Station. In most systems, the terminations should be in the ON position (default setting). Clear-
Com Power Supplies also provide switch-selectable termination networks on all intercom lines. Re-
fer to the User manual for the specific Main Station or Power Supply for the exact location. It is up
to the user to ensure that the terminations are set correctly. An unterminated line will cause exces-
sive levels, possible oscillation of line drivers, and squealing in the headsets. An intercom line with
double or multiple terminations will cause low levels and the inability to null the headsets.
The termination switches on a Main Station should be set to the OFF position
only
if the channel is
terminated by another Main Station or Power Supply in the system.
If there are no other Main
Stations or Power Supplies terminating the line, the termination switch on each channel of
the Main Station should be switched to ON.
Headset Connector:
The headset connector is located on the front panel of all stations. Clear-
Com headsets are recommended, but others can be used if they meet the following requirements:
Mic Type --- Dynamic; 150 to 250 ohms impedance; -55 dB output level
Headphone --- Dynamic; 50 to 2000 ohms impedance
Clear-Com System Installation Manual
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